The present invention concerns data input devices and relates more particularly to an entirely electronic device which makes use of the principle of progression of data in response to movement of a finger over responsive sensors.
The principle of progressively moving a group of data across a display and stopping the progression when the piece of data displayed corresponds to that desired, has been widely used for the purposes of data entry. For example, when setting the correct time on a digital display of watch, time data is progressively displayed until the proper time is reached.
A device which makes it possible to cause data to move across a display by acting on a push button is known for example from the present applicants' Swiss Pat. No. 533,332. Such a device is found too inconvenient when there is a large number of data as the speed of progression must necessarily be slow in order to permit visual monitoring of the data. The present applicants' U.S. Pat. No. 4,242,676 discloses other data input devices in which data progression, the speed of which depends on the speed of movement, is produced in response to movement of a finger of an operator over sensors. In the latter devices, the direction of progression of the data depends on the order in which the sensors are activated and the speed of progression is variable, but the number of symbols is limited. British patent applications Nos. 2,019,049A and 2,019,052A describe electronic devices for correcting displayed information on a watch, wherein the correction operation is controlled by rotation of the setting crown of the watch. In the first application, the direction of rotation of the setting crown determines the correction function (correction in respect of the time or correction in respect of date) and the correction pulses which are delivered by the described device are at a first or second frequency, depending on the speed of rotation of the crown. In the second application, the same correction control principle is used but on the one hand the direction of rotation of the crown determines the direction in which the correction is made and on the other hand the device can produce more than two correction pulse frequencies, depending on the speed of rotation of the crown. The latter devices suffer from the disadvantage of employing a mechanical and therefore generally unreliable control member. Moreover, the provision of only two speeds of correction is found to be inconvenient.